Aim: To assess the efficacy and safety of tadalafil in comparison to a placebo, when taken on demand for 12 weeks by East/Southeast Asian men with erectile dysfunction (ED).

Methods: This multicenter, randomized, double-blind, parallel group, placebo-controlled study was conducted at 17 centers across East and Southeast Asia between August 2002 and February 2003. Men more than 18 years of age with mild to severe ED of various etiologies were randomized to receive a placebo or 20 mg of tadalafil taken as needed (maximum once daily). Efficacy assessments included the International Index of Erectile Function, the Sexual Encounter Profile diary and Global Assessment Questions.

Results: Tadalafil significantly improved erectile function as compared to the placebo (P < 0.001). At the endpoint, the patients receiving 20 mg of tadalafil reported a greater mean per patient percentage of successful intercourse attempts (Sexual Encounter Profile question 3: 70.9% compared to 33.5% in the placebo) and a greater proportion of improved erections (Global Assessment Question: 86.2% compared to 30.1%). Most ( 3%) treatment emergent adverse events were mild or moderate. The most common treatment emergent adverse events were headache, back pain, dizziness and dyspepsia.

Conclusion: Tadalafil was an effective and well-tolerated treatment for ED in East and Southeast Asian men.